1. Field of the Invention
The present invention relates in general to a device for quickly removing a door without penetrating the door with a projectile, more particularly, the present invention relates to a cartridge assembly which can be fired from a launcher or gun at a substantial distance from a door to effect rapid and relatively non-destructive knockdown of the door without posing a safety hazard to the operator of the launcher or gun.
2. Description of the Related Art
Israeli Patent No. 106629 teaches a door breaching system which includes a device, illustrated in a side view in FIG. 1, which has a stabilizer body 60 for stabilizing the device during its flight to the proper location, namely, into contact with the object, typically a door, to be removed. Stabilizer body 60 typically includes a tail or wings to aid in aerodynamically stabilizing the launched projectile. Stabilizer body 60 may be of any suitable type including, but not limited to, any of a wide variety of suitable conventional or known stabilizer bodies which can be used in conjunction with various launched grenades, mortars, and the like. The illustrative stabilizer body 60 depicted in FIG. 1 is similar to that commonly used to stabilizer anti-tank projectiles.
This device further includes a shaped explosive charge 62, preferably including high explosive. Explosive charge 62 is shaped to effectively breach the object, e.g., a door, without causing more than minimal damage to persons and property near and beyond the door, when explosive charge 62 is detonated at a preset distance from the door. Preferably, the anterior face of shaped explosive charge 62 is substantially spherical, but many other shapes may be effective, depending largely on the nature and dimensions of the object to be breached, and on the distance from the object at which the explosion is to take place.
Shaped explosive charge 62 is located in a housing 64 designed to allow the force of the explosion to be directed anteriorally rather than posteriorally. Housing 64 may be made of any suitable material, preferably, housing 64 is made of a suitable plastic so as to limit the formation of dangerous shrapnel and thereby minimize potential injuries to personnel on both sides of the door being blasted.
Connected to housing 64, or integrally formed with it, is a stand-off rod 66 of suitable length. Preferably, housing 64 and stand-off rod 66 are two discrete items which are readily connected to each other. Such an arrangement makes it easier to transport the disassembled device with rods 66, housings 64 containing shaped explosive charges 62, and stabilizer 60 housed separately for easy storage and rapid assembly. The connection of stand-off rod 66 to housing 64, when present, may be of any suitable type, including, but not limited to, by screwing or snap-fitting rod 66 into housing 64, and the like. Rod 66 may be made of any suitable material, including, but not limited to, plastic and metal.
The length of stand-off rod 66 and the type, amount and shape of shaped explosive charge 62 are selected to optimize the ability of the device to effectively remove the door, without injuring persons or other property in the vicinity.
Preferably, stand-off rod 66 has connected to its anterior end an impact disc 68 having an effective diameter larger than the effective diameter of standoff rod 66. Impact disc 68 may be integrally formed with stand-off rod 66. Preferably, impact disc 68 is disc-shaped. The presence of impact disc 68 is intended to enlarge the area of direct impact with the door so as to lower the pressure at the point of impact and thus reduce or eliminate the possibility of stand-off rod 66 penetrating the door, thereby reducing the effectiveness of the device and potentially injuring persons and damaging property located beyond the door.
Included in the device is a suitable detonating means for detonating shaped explosive charge 62 substantially upon impact of the anterior end of stand-off rod 68 with the object, e.g., the door.
The detonation can be effected in any of a number of ways, including, but not limited to, by transferring the impact from the stand off rod to a striker which initiates an initiator. The detonation is transferred to a lead pellet 70 which detonates explosive charge 62.
This device also includes a “safe-and-arm” device (SAD) 72 of suitable design which prevents accidental or premature detonation of the device, as is commonly used in various current applications. SAD 72 may, for example, be selected to arm shaped explosive charge 62 only after a pre-selected time period has elapsed after the device has commenced to be propelled toward its target, or after the device has been propelled through a pre-selected distance. SAD 72 may, for example, operate by bringing into alignment initiator and lead pellet 70 and shaped explosive charge 62 only after a certain period of time after launching of the device. SAD 72 prevents the accidental detonation of the device, but typically requires that the device be fired from beyond a certain minimum distance.
To use the device, the operator connects a stand-off rod 66 to housing 64 of shaped explosive charge 62. The operator mounts stabilizer 60 onto a suitable launcher (not shown), such as a grenade launcher or suitable gun. Alternatively, stabilizer body 60 could be replaced by a self-propelling device (not shown), such as that used in RPG rockets. Preferably, however, the device is mounted onto a suitable launcher or gun which provides the propulsion required to deliver the explosive over the relatively short distance between the launcher and target. The operator aims at the optimal point on the object, such as a door, and fires the launcher, propelling the device toward its target.
Upon impact of the anterior end of stand-off rod 66 with the door, the initiator located in SAD 72 detonates pellet 70 (assuming SAD 72 was already armed) which, in turn, immediately sets off shaped explosive charge 62. The created explosion pressure waves spread in a way which depends on the nature, shape and quantity of the explosive used and on the distance from the target at the moment of explosion, which is determined largely by the length of stand-off rod 64.
The device of Israel Patent No. 106629 clearly has many advantages for rapid and relatively non-destructive knocking down of doors. However, given the short ranges over which it is typically used, the device can pose a potential hazard to the device operator and other personnel in his proximity. Specifically, due to the force of the explosion, there is a risk that part or all of stabilizer body 60 may be propelled rearwards at high speed and strike the operator or others nearby.
Thus, there is a need for a device generally similar to the device described above for quickly and effectively breaking down a locked door which will not pose a safety hazard to the operator and other personnel in his vicinity.
U.S. Pat. No. 6,408,765 discloses a door breaching device shown in FIG. 2 which can be used to remotely blow away doors with less risk of damage to the operator or to persons and property near and beyond the door.
FIG. 2 is a side view of such a breaching device, generally designated 30, constructed and operative for controlled blasting of an object at short range.
Breaching device 30 is similar to the device of Israel Patent No. 106629 described above with reference to FIG. 1. Thus, breaching device 74 includes a blasting element 76 including an explosive charge 78 contained within a housing 80. Blasting element 76 is configured to breach the door or other object from a preset distance. Connected to, and extending from, housing 80 is a stand-off rod 82 having a length equal to the preset distance. Typically, standoff rod 82 is connected at its anterior end to an impact disc 84 which has an effective diameter larger than the effective diameter of stand-off rod 82.
The device includes a suitable SAD 88 which prevents accidental or premature detonation of the device, as is commonly used in various known applications. SAD 88 may, for example, be selected to arm shaped explosive charge 78 only after a pre-selected time period has elapsed after the device has commenced to be propelled toward its target, or after the device has been propelled through a pre-selected distance.
A detonator located inside SAD 88 is associated with blasting element 76 and stand-off rod 82, so as to detonate explosive charge 78 substantially upon impact of stand-off rod 82 with the object. Housing 80 preferably contains a lead pellet 86 which transfers the detonation from SAD 88 to explosive charge 78. A tail 90 stabilizes device 74 during its flight to the object.
Tail 90 connected to blasting element 76 through a safety connector 92 is configured to reduce shock forces acting on tail 90 resulting from detonation of explosive charge 78. This serves to diminish the risk of tail 90, or any part thereof, being propelled rearwards in a manner that could cause injury to the operator or other personnel in his vicinity.
Projectiles that radially expand upon impact with a target are known in the art. Many are comprised of a soft deformable material, such as lead, so they undergo some axial compression and radial expansion upon impact. Others are specifically designed to produce radial expansion. One approach taken in the prior art is to include a cavity in the leading end of the projectile, a so-called “hollow point.” Another approach includes a cavity in the leading end of the projectile, with a tip or piston in the cavity which is driven into the cavity by the impact with the target, causing radial expansion.
A third approach also includes a cavity. The cavity is filled with a substance or liquid that causes radial expansion. U.S. Pat. No. 5,349,907, Petrovich et al., discloses a projectile with a fluid filled cavity and a shaft disposed in the cavity aft of the fluid. Upon impact, the shaft is driven into the fluid, and compressive pressure on the fluid causes radial expansion. U.S. Pat. No. 3,429,263, Snyder et al., discloses a projectile with a paint-filled cavity that is used for marking targets at a distance. The Snyder patent claims radial expansion of the projectile due to compressive pressure on the paint upon impact.
Rousseau, in U.S. Pat. No. 1,715,788, discloses a hollow point projectile with a cavity, that when filled with fluid by impact with soft tissue, causes radial expansion of the projectile. U.S. Pat. No. 1,512,026, Holden et al., teaches a projectile with a fluid-filled tip attached to the leading end. Upon impact with a target, the compressive pressure on the fluid in the tip is conveyed by a depression in the core of the projectile, or by a jacket that surrounds the core, and causes radial expansion of the projectile.
Prior art projectiles with fluid-filled cavities achieve radial expansion upon impact. However, the Petrovich, Snyder and Holden projectiles each require special manufacture at increased cost. The Rousseau projectile achieves radial expansion only on impact with soft, fluid-rich tissue, a drawback if the projectile strikes boney or thin tissue. These inventions lack a structure and method to mass produce an insert that will create a projectile with consistent expansion properties.
U.S. Pat. No. 7,373,887 discloses a projectile comprising a body having a channel, one or more recesses in the channel, a plunger in the channel, and a fluid in the channel. When the projectile impacts a target, the plunger is driven down the channel, exerting a force on the fluid. The fluid, in turn, exerts fluidic pressure within the recesses, promoting rapid yet predictable expansion of the projectile.
Some projectiles in the art use a cylindrical fluid-filled cavity to exert a radial expanding force. Fluid-filled bullets offer several advantages over hollow-point and ballistic-tip bullets. First, there is no hollow point to clog or malfunction as in a hollow-point bullet. Second, fluid-filled bullets can expand more rapidly than either hollow-point or ballistic-tip bullets. Fluid-filled bullets can offer greater expansion at a given velocity than either a hollow-point or a ballistic-tip bullet.
U.S. Pat. No. 6,675,718 to Parker discloses a method for making a fluid-filled projectile by first assembling a fluid-filled cylinder or capsule, and then inserting the cylinder into a hollow cavity of a bullet.
Despite the potential advantages of fluid-filled projectiles as taught by the prior art, they have had extremely limited to no commercial success. A primary reason for the lack of success is the fact that prior art fluid-filled projectiles exhibit unpredictable and uncontrolled expansion on a round-per-round basis. Predictable expansion is a primary factor when the military, law enforcement agencies, or hunters choose which projectile they are going to use. Accordingly, the military, law enforcement agencies, and hunters have not adopted fluid-filled bullets.
U.S. Pat. No. 1,114,356 to Hoaglund discloses a tip of the bullet fully jacketed. The jacket is made in two parts, a nose portion and a body portion. The nose portion includes longitudinal grooves of a thinner section rearward of the nose itself which promote collapse upon impact. Upon impact, the nose section slides over the rear portion and expands “umbrella-like”. Although this concept may serve certain applications, the unsupported rear of the resulting “umbrella” is also likely to collapse under stress. This impairs the ability of the bullet to retain and control sufficient radial expansion. In addition, a more conventional jacket of a single piece is less complex, and is easier and less costly to manufacture.
An early accordian concept employing a single piece jacket is found in U.S. Pat. No. 594,199 to Field. That design, however, lacks any additional means to facilitate nose collapse and expansion. Thus, deformation and expansion depend greatly upon target hardness. In cases of impact only with soft tissue or at slower speeds, the solid nose may well fail to collapse at all. It should be noted that the longated longitudinal holes around the projectile nose of Field are not ‘slits’, but rather ‘cutouts’ which are milled or ground into the nose. Their thin, knife-like borders are stated to be for a different purpose, presumably for cutting. Such gaping holes, however, also distort the desired aerodynamically smooth profile and weaken the nose jacket, exposing more soft core material, and rendering the nose more likely to burst or fracture upon impact with harder, honey target material.
U.S. Pat. No. 1,155,901 to Duncan discloses a hard nose insert. Duncan provides no jacket slits nor other means of weakening the jacket to aid or to control radial expansion. It appears that in many situations, no radial expansion would take place. Moreover, upon impact with harder targets, where sufficient force is encountered, the jacket very easily could burst and ramdon expansion or even disintegration ensue. Because the insert is not cylindrical, it would also, apparently, be very difficult to insert into the nose making the bullet more difficult and costly to manufacture.
Thus, it is an object of the present invention to provide a fluid-filled projectile that expands in a predictable manner. Such a projectile would be useful in numerous military and law enforcement applications.
It is another object of the present invention to provide a device for breaching a door which limits and minimizes any danger to the operator or nearby personnel caused by blow back of components or fragments from the device itself.